Trauma- and stressor-related disorders involve exposure to a traumatic or stressful event. Two of the trauma-related disorders are acute stress disorder and posttraumatic stress disorder (PTSD). Acute stress disorder and PTSD are similar except that acute stress disorder typically begins immediately after the trauma and lasts from 3 days to 1 month, whereas PTSD lasts for > 1 month, either as a continuation of acute stress disorder or as a separate occurrence that begins up to 6 months after the trauma.
Previously, trauma- and stressor-related disorders were considered anxiety disorders. However, they are now considered distinct because many patients do not have anxiety but instead have symptoms of anhedonia or dysphoria, anger, aggression, or dissociation.